The present invention relates to an arrangement for introducing waste material into a molten slag which occurs in a cupola furnace.
Under the environmental protection decrees, which are becoming ever more stringent, particularly high demands are made on the operation of cupola furnaces.
During the smelting process various metals evaporate in the cupola furnace, which metals are contained in the scrap portion, such as, for example, zinc, cadmium, lead, etc., and may no longer be carried away into the open air on account of pollution abatement regulations of the air, but are caught with the aid of a filter unit.
In particular a method is known by which the dust particles as waste material are introduced into a molten furnace slag such that they are fed underneath the slag surface in the slag overflow with the aid of a worm conveyor and are vitrified.
The disadvantage of this method is above all the fact that as a result of the high scrap content during the smelting process the filter dust contains dangerously high zinc values. As the filter dust is now introduced into the slag in the direct vicinity of the slag overflow, as a result of the high zinc contents the lining is attacked and wears. This results in a changed siphon geometry, this being linked with disadvantages for the cupola furnace operation, as with a non-tight siphon the air blast escapes.
Basing considerations upon this prior art, it is the object of the present invention to put forward an arrangement for introducing waste material into a molten slag which occurs in a cupola furnace, with the aid of which arrangement economical, process-reliable and reproducible waste disposal is possible in order to avoid dumping which loads the environment and gives rise to costs.